Plasma protein receptor purification.

[Dima Klenchin]

s010867 at mailserv.cuhk.edu.hk (Daniel) wrote:
>Dear all,
>
>I wanna isolate receptor protein from culture cell. The theoretical
>pI/Mw of that protein is 8.53/78KDa. I've tried several methods but I
>couldn't get any postive signals from my western blotting. I think it
>maybe the result of low abundance of that protein on these cell. Can
>anybody give me some suggestion on the receipe of buffer and better
>methods for  me to isolate these protein?

First, you must find a detergent that keeps your receptor active
after membrane solubilization. Second, you must have a working 
deytection system (Western or ligand binding). 

Given that, two generic purification steps are obvious: 
affinity chromatogrphy on immobilized ligand and cation exchange
(S- or CM-based, whichever works best) at ~ neutral pH. 

        - Dima